CC chemokine receptor type 7 (CCR7) and its ligands has been implicated in the occurrence and progression of NSCLC. Previous studies have revealed that the diagnostic value of CCR7/CCL19 axis in lung tumorigenesis remains controversial. The present study evaluates the relationship between the mRNA expression of CCR7/CCL19 axis and selected regulatory miRNAs in NSCLC patients. It analyzes the expression level of CCR7 mRNA and its ligand in tumor tissue in relation to expression level of two miRNAs: miR let-7a and miR-335, as transcriptional regulators of study genes. Twenty-seven patients (n = 27) were enrolled. The expression of the studied genes and miRNAs was evaluated by qPCR. Tumour tissue fragments, adjacent macroscopically-unchanged lung tissue (control) and patient serum were used as biological material for study. Elevated expression of CCR7 and CCL19 mRNA was observed in patients with metastasis to lymph nodes. We noticed upregulated miR-335 expression and downregulated miR let-7a expression in patient serum with regard to AJCC tumor staging. Higher miR-335 expression and lower miR let-7a expression level was observed in patients with metastasis to lymph node. The presence of changes observed in the expression level of miR-335 and miR let-7a in the serum of NSCLC patients in relation to lymph node metastases and tumor stage may serve as a non-invasive molecular biomarker of tumor progression; however, this observation requires further investigation.

This article is available in open access under Creative Common Attribution-Non-Commercial-No Derivatives 4.0 International (CC BY-NC-ND 4.0) license, allowing to download articles and share them with others as long as they credit the authors and the publisher, but without permission to change them in any way or use them commercially.

A pro-inflammatory cytokine, IL-17A, is associated with increased risk of developing numerous cancers, including nonsmall cell lung cancer (NSCLC). IL-17A is a target gene for miR-9. This encouraged us to analyze these two genes in terms of their usefulness as prognostic markers in NSCLC. The expression levels of IL-17A gene and miR-9 was assessed in 26 NSCLC tissue samples and 26 unchanged lung tissue adjacent to lung tumors (control tissue), using qPCR. In both tissue groups, a decreased expression of IL-17A was observed in 100% of samples. Increased expression of miRNA-9 was observed in 92% of tumor samples, and in 100% of control samples. Neither statistical differences in the level of expression IL-17A depending on the patient's age, gender, smoking status, nor histopathology of the cancer was found. Regarding the presence of nodule metastasis ('N' value in TNM classification), significantly lower expression level of IL-17A was observed in cN2 as compared with cN1 group. Additionally, statistically lower IL-17A expression was found in III versus II tumor stage (cAJCC classification). Significant negative correlation between both studied genes was revealed in SCC subgroup. This leads to the conclusion that miRNA-9 can regulate the expression of IL-17A as an IL-17A mRNA antagonistic mediator. Inhibition of proinflammatory action of IL-17A in correlation with tumor progression can be related to various activity of Th17 cells on cancer development according to its immunogenicity, and also may suggest suppressive role of IL-17A in tumor progression. However, because of low number of analyzed samples, further studies on the functional role of IL-17A in development and/ or progression NSCLC seem warranted.

The chemokine receptor 7/C-C ligand 19 chemokine (CCR7/CCL19) has been implicated in the development and progression of NSCLC. Its expression is regulated by various epigenetic factors including miRNAs. The aim of this study was to assess the expression of CCR7/CCL19 in cancer tissue in relation to that of miRNAs (miR-let-7a, miR-335) as transcriptional regulators. The expression of the tested miRNAs was also evaluated in serum exosomes. Sixty patients (n = 60) were enrolled in the study. The total expression of the studied mRNA and miRNAs were evaluated using qPCR. Tumor tissue fragments, macroscopically unchanged adjacent tissue, and serum were used as controls. Higher CCR7 and CCL19 mRNA expression levels were observed in tumor tissue compared to control. According to stages of the disease (AJCC tumor staging), the greatest expression level of the studied genes’ mRNA was observed in patients with stage III. In NSCLC patients, lower miR let-7a expression level was observed in tumor tissue compared to serum; however, miR-335 expression level was higher (p < 0.05). The expression level of miR-335 positively correlated with tumor size (T features according to pTNM staging) and AJCC tumor staging, while miR let-7a had a negative correlation (p > 0.05) with liquid biopsy. Significantly greater miR-335 expression level and lower miR let-7a expression level in serum were observed in patients with metastases to lymph nodes. Our findings reveal a significant correlation between the expression levels of the mRNA of the studied genes and miRNAs. Changes in miR-335 and miR let-7a expression levels in the serum exosomes of NSCLC patients in relation to lymph node metastases and tumor stage may serve as a non-invasive molecular biomarker of tumor progression.

The C–C motif ligand 20 (CCL20) is a chemokine that specifically binds to the chemokine receptor 6 (CCR6) and the CCL20/CCR6 axis has been implicated in the non-small lung cancer (NSCLC) development and progression. Its expression is regulated by mutual interactions of non-coding RNAs (ncRNAs). This goals of presented study was to evaluate the expression level of CCR6/CCL20 mRNA in NSCLC tissue comparative to selected ncRNAs: miR-150, linc00673. The expression level of the studied ncRNAs was also assessed in serum extracellular vesicles (EVs). Thirty patients (n = 30) were enrolled as the study cohort. Total RNA was isolated from tumor tissue, adjacent macroscopically unchanged tissue and serum EVs. The expression level of studied genes and ncRNAs were estimated based on the qPCR method. Higher expression level of CCL20 mRNA but lower expression level of CCR6 mRNA were observed in tumor in comparison to control tissue. Relative to the smoking status, higher CCL20 (p < 0.05) and CCR6 mRNA (p > 0.05) expression levels were observed in current smokers than in never smokers. In serum EVs the expression level of miR-150 has a negative correlation with AJCC tumor staging, whereas the expression level of linc00673 positively correlated (p > 0.05). The lower expression level of miR-150 and higher expression level of linc00673 in serum EVs were observed in NSCLC patients with lymph nodes metastases (p > 0.05). Regarding the histopathological type, significantly lower expression level of miR-150 and higher expression level of linc00673 were observed in the serum EVs of patients with AC compared to patient with SCC. Our findings revealed that smoking significantly changed the expression level of CCL20 mRNA in NSCLC tissue. Changes in expression levels of miR-150 and linc00673 in the serum EVs of NSCLC patients in relation to presence of lymph node metastases and the stage of cancer development may serve as a non-invasive molecular biomarkers of tumor progression. Furthermore, expression levels of miR-150 and linc00673 may serve as non-intrusive diagnostic biomarkers differentiating adenocarcinoma from squamous cell carcinoma.